x1,y1,x2,y2=map(float,input().split())

z=((x1-x2)**2+(y1-y2)**2)**0.5
print("{0:.5f}".format(z)) x1,y1,x2,y2=map(float,input().split()) x1 map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 z=((x1-x2)**2+(y1-y2)**2)**0.5 z ((x1-x2)**2+(y1-y2)**2)**0.5 (x1-x2)**2+(y1-y2)**2 (x1-x2)**2 x1-x2 x1 x2 2 (y1-y2)**2 y1-y2 y1 y2 2 0.5 print("{0:.5f}".format(z)) print "{0:.5f}".format(z) "{0:.5f}".format "{0:.5f}" format z x1,y1,x2,y2=map(float,input().split()) map(float,input().split()) x1 y2=map(float,input().split()) map(float,input().split()) y2 z=((x1-x2)**2+(y1-y2)**2)**0.5 ((x1-x2)**2+(y1-y2)**2)**0.5 z x2,y2=map(float,input().split()) map(float,input().split()) x2 y1,x2,y2=map(float,input().split()) map(float,input().split()) y1
x1,y1,x2,y2=map(float,input().split())

z=((x1-x2)**2+(y1-y2)**2)**0.5
print("{0:.5f}".format(z))
